Anthracycline antibiotics including doxorubicin, daunorubicin, and carminomycin are important chemotherapeutic agents in the treatment of a broad spectrum of neoplastic conditions including acute myeloblastic and lymphoblastic leukemias. Doxorubicin (also known as Adriamycin) is the subject of U.S. Pat. No. 3,590,028 and is a prescribed antineoplastic agent used in a number of chemotherapeutic treatments. Specifically, doxorubicin and daunomycin have the formula: ##STR2## with the compound being doxorubicin when R is --OH and daunomycin when R is --H.
In view of the proven effectiveness of known anthracyclines in the treatment of cancer, efforts have been undertaken to develop less toxic derivatives which can be administered in high, more effective dosages with greater frequency.
U.S. Pat. No. 4,046,878 to Patelli et al. discloses daunomycin analogues substituted at the 1-position and/or the 4-position with chlorine or bromine.